Lebedev, Pyotr Nikolaevich

Lebedev, Pyotr Nikolaevich pyô´tə nyĭkəlī´əvĭch lā´byədyəf [key], 1866–1912, Russian physicist. The most noted Russian physicist of his time, he studied at Strasbourg and Berlin and was professor at Moscow Univ. He was the first to measure the pressure of light, confirming predictions based on Maxwell's equations. He was also the first to show that this pressure is twice as great for reflecting surfaces as for absorbing surfaces.